Woven mat

ABSTRACT

An assembly for preventing erosion of sand and pebbles from shores, beaches, waterways and the like. The assembly includes an outer mat made from a thermoplastic material. The mat has an open net weave and includes several compartments which are adjacent one another. A plurality of open net weave bags, also made of thermoplastic material, and filled with entangled ribbons of thermoplastic material are inserted into the compartments of the mat. The assembled mat may be attached to the shore.

[ 51 Oct. 10,1972

United States Patent Heine et al.

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u m m u m m ma "a e wmfiamm m mwamam Sm TvNNs 2679900 56667777999.999999 WHWWWWUZZ r11 1 9990024 97 790211113 J ,J wnufifinwma23333333 I D we. mm G M a a mm m 6 MM W W m H m l o m r 6W 0F K v i 9 g8 mm mmm y n v. mm m M 3 M C hm FS& G N a. K a n m. 0 v a W .m A m n nrlL [22] Filed: June 1971 Primary Examiner-Reinaldo P. Machado AssistantExaminer-Philip C. Kannan Attorney-Curtis, Morris & Safl'ord [21] Appl.No.: 158,036

Related US. Application Data [63] Continuation-in-part of Ser. No.843,518, July [57] ABSTRACT An assembly for preventing erosion of sandand peb- 22, 1969, abandoned.

bles from shores, beaches, waterways and the like. The assembly includesan outer mat made from a ther- [30] Foreign Application Priority Datamoplastic material. The mat has an open net weave July 30, 1968Germany..........P 17 84 360.6.

and includes several compartments which are adjacent one another. Aplurality of open net weave bags, also 829 BHM n w i 00 E5 m m 8 m 3 m 7u 3 n l l m uh c "Ham L mt o W Smk UlF 1]] 218 556 [56] References CitedUNITED STATES PATENTS 11 Claims, 4 Drawing Figures "984,121 2 1911Condie. .................6l/38 PATENTEDnm 10 m2 sum 1 or 2' PATENTEDBBI10 I972 SHEET 2 OF 2 WOVEN MAT This application is acontinuation-in-part of my copending application Ser. No. 843,518,entitled Woven Mat," and filed on July 22, 1969, now abandoned.

The present invention relates generally to woven mats, and particularlyto mats for use in preventing erosion of shores, beaches, waterways andthe like.

Heretofore, a number of proposals have been offered to preventtheerosion of sand and other materials from beaches and waterways. Most ofsuch attempts have involved massive and difficult installationsrequiring heavy machinery for both initial construction and repair andreplacement. Because of its sheer mass, erosion-preventing installationsof this kind, cannot be either quickly or inexpensively set up toprovide effective and permanent protection.

It has been observed that lightweight seaweed washed ashore has atendency to retain sand and pebbles which have been drifted by the windsor washed ashore, and thus are the starting point of the naturalformation of small sand hills. The band or ribbon-like structure ofseaweed is particularly favorable to theformation of such hills, andother band-shaped spacial units will also accumulate sand and pebblesand thus retard erosion.

Satisfactory coastal preservation cannot be achieved by looselyspreading band-shaped spatial units, for example, strips of plasticfilms or sheets, on the shore. Such unsecured spatial units soon blowaway in the wind and wash away in the water, and do not remain in theplaces where they are needed to build up the sand dunes and preventerosion.

We have now found that excellent erosion protection is offered bysplicing together and/or entangling ribbons of thermoplastic material,stuffing this material into a net sack or bag (also preferably made ofthermoplastic material); inserting this net sack stuffed with thespliced entangled ribbons of thermoplastic material into preparedcompartments of a large mat (also made of thermoplastic material). Thecompartments which hold the stuffed net sacks, have an open net weave.In one embodiment, the net compartments of the mat are separated onefrom another by strips of material. These strips of material may befastened into'the beach, such as with pegs or other suitable means. Withthis arrangement, the mat is held in place on the beach or other area tobe protected. In place of the strips seams may be formed by sewing thetwo layers of mat netting together, so as to define the compartments.

In summary, the ribbons or bands of thermoplastic material are entangledone with another to form balls or cushions, and these balls retard theerosion. The ribbons or bands are held in place by the inner bag, whichin turn is held in place by the outer compartment. The

compartments are held in place by the mat which is fastened to thebeach. The net bags and net compartments also assist in retardingerosion. Thus, the materials which retard erosion are uniformly spreadout over the beach, and are not easily moved by the water or blown abouton the beach, as is the case with. strips, which are free to rise andfall with the tides. The double net, and long ribbons of materialinteract to further retard erosion and loss of the erosion-preventingmaterial. Should one of the nets become broken, there is a double net.Should one, or both, become broken, the

long ribbons become entangled with a broken net and thus the ribbons areless easily washed out.

It is desirable that when enmeshed together the ribbons of thermoplasticmaterial, which fill the inner bags, be long, and fairly compact. If thebags should become ruptured, shorter ribbons tend to wash out, but theirlength and compactness of intermeshing will tend to retain the ends ofthe ribbon in the inner and outer netting, and the floating or partiallyfreed ribbons will achieve the purpose of preventing the erosion.

As the woven mat, constructed in accordance with this invention, remainson the beach or other area to be protected, sand drifted by the wind,and washed ashore by the water, is kept in the entangled ribbons offilms or sheets in a manner such that the sand accumulates in the mat.Within a short time, the mat is completely filled with sand, and offerseffective protection, and typically is not even removed by heavy stormsor beating waves. As one layer of mats becomes covered, or even in theoriginal installation, it is possible to put one or more mats on top ofthe first ones, so that they all become filled with sand in the sameway. Thus, the erosion of beaches can be effectively reduced and thecoastline preserved.

- It is important to note that the mat compartments and the bags of thepresent invention are not filled with a heavy material, such as rocks orwood. This greatly facilitates installation. The inner bags are quitelight, and in a typical installation are prepared separately from theouter mats and the large outer mats can be rolled up for transportation.At the site, the inner bags are merely inserted into the compartments inthe mat. If it is necessary to repair or replace one mat on the beach,its fastening to the ground is removed, the inner bags may be pulledout, and the outer mat is then rolled up and carried off. In practice,it is envisioned that the size of the mats will be of a manageable size,e.g. 10 meters by 10 meters, so that they can be easily handled by oneor two men, without the aid of machinery. As noted, the mat and bags,and fill in the bags are of a thermoplastic material, and therefore,quite light.

Further, it will be appreciated that because of the light weight of thebags and mats, and because of their flexibility, they can be easilytransported to remote locations which heavy equipment may findinaccessible, and where they can be laid down to prevent erosion.

According to one aspect of the invention, for securing coastlines thereis provided an assembly having a large outer mat made of a thermoplasticmaterial with an open net weave. Seams, or tight strips of fabric,divide this outer mat into several compartments. A number of bags, alsomade of thermoplastic material and having an open net weave, are filledwith spliced or entangled strips or ribbons of thermoplastic material.These bags are then inserted into the several compartments of the largeouter bag.

The above and other objects, features and advantages of this inventionwill be apparent in the following detailed description of illustrativeembodiments thereof which are to be read in connection with theaccompanying drawings wherein:

FIG. 1 is a plane view of one embodiment of a mat constructed inaccordance with the invention.

FIG. 2 is a cross sectional view of the mat of FIG. 1.

FIG. 3 is a plane view of an alternative embodiment of a mat of thisinvention.

FIG. 4 is a cross sectional view of the mats of FIGS. 1 and 2, fastenedto the ground.

Referring now to FIGS. 1 and 2, there is shown a mat having a borderstrip of fabric 1, and several intermediate strips of fabric 3 parallelto the border strip, and strip, and double layer woven nets 2 attachedbetween adjacent strips. All of these strips 1 and 3 are of a tightfabric, and the woven net 2 is of an open net. The two layers of netbetween adjacent strips define several compartments. This is shown mostclearly in FIG. 2. Into these compartments there is inserted large bags2a of similar dimensions to the compartments. These bags 2a are also ofa woven net, or have an open net weave. Typically, the net of the innerbags 2a may be tighter than the open net of the compartment 2. The bags2a are filled with thin polyethylene ribbons, or films, or sheets whichare loosely fitted and entangled with one another to form balls, and maybe spliced together to form long ribbons or long spatial shapes. Theseenmeshed balls of ribbons are indicated generally as 2b in FIG. 2. Themats 1, 2, 3 and the bags 2a and the fill material 2b are all made ofthermoplastic material. The fill material is typically polyethylene, andmay come from waste products obtained in the working of plastics. Ifthese waste products are short in length, it is desirable that they bespliced together so as to form long spatial shapes, because long fill isnot so easily washed out of the bags and compartments in the event thenets should become broken. The material for making the nets of both themat 2 and the bags 2a, is preferably low pressure polyolefins, lowpressure ployethylene, copolymers of ethylene and propylene, orpolypropylene. It is also possible to use several differentthermoplastic materials; for example, the strips of fabric 1 and 3 maybe of one material, the netting 2 and 2a of another, and the fill filmsor sheets 2b of still another. The assembly is exposed to intenseatmospheric influences, and the polyolefins are advantageously combinedwith light stabilizers, for example, soot. It is not absolutelynecessary to manufacture the mat from drawn strips of films or sheets;it may also be made of monofilaments of thermoplastic material. Thewoven net used for the compartments 2 and the bags 2a is advantageouslyof a leno-weave. It is, however, also possible to use netting of otherweave.

Referring now to FIG. 3, there is shown an alternative embodiment to thepresent invention. The mat here has an outer fabric strip 10 with adouble netting 12 between the outer fabric strip 10. The netting 12 isdivided into cushions of netting 5, which are sewn in a quilt-likemanner disposed on the mat 12. The cushions of netting are filled withribbons, films, or elongated sheets of thermoplastic material of thesize and shape previously described.

As shown in FIGS. 1 and 3, the strips of fabric 1, 3 and are providedwith eyelets 4 and 14 to facilitate securing the mats to the shore orother surface which is to be protected. This can be best seen in FIG. 4which is a cross sectional view of the mat of FIGS. 1 and 2 attached toa shore. As shown in this Figure, the outer strips 1 of the mat havetent-pegs 6 driven through the eyelet portion in the end strips 1 of themat. The tentpeg or other type of fastener, such as other peg or pile,

is driven into the ground through the eyelet. It is also possible toprovide the borders of the strips of the fabric with pockets which arethe n filled with sand or stone and t en lard on the groun to beprotected. It

may, furthermore, be advantageous to load the surface of the mat withsand or pebbles to prevent the mat from slipping or from being lifted byhigh winds or waves.

Thus, there has been shown and described a novel assembly for preventingerosion, and for building up shorelines. Because of its design, and thechoice of materials, it is easily, rapidly and manually installed. Thedouble net construction of the invention facilitates manufacture andstorage with the ribbons or films which retard the erosion, and can bestored in the inner bags while waiting to be inserted into thecompartment of the mats. The thermoplastic material is not onlylightweight (and thus easy to transport and to install) but also isresistant to the elements and is inexpensive.

Although illustrative embodiments of this invention have been describedin detail herein with reference to the accompanying drawings, it is tobe understood that the invention is not limited to those preciseembodiments, and that various changes and modifications may be effectedtherein by one skilled in the art without departing from the scope orspirit of the invention.

What we claim is:

' 1. An assembly for inhibiting shore erosion and the like comprising alarge outer mat, said mat being made of thermoplastic material andhaving an open net weave; means for dividing said mat into severalcompartments; a plurality of bags inside said mat compartments, saidbags being also made of thermoplastic material and having an open netweave; and entangled strips of thermoplastic material filling the innerbags.

2. An assembly according to claim 1, wherein said means for dividingsaid mat are tight strips of fabric.

3. An assembly according to claim 1, wherein said means for dividingsaid mat are seams.

4. An assembly according to claim 1, wherein said strips ofthermoplastic material are spliced.

5. An assembly according to claim 1, wherein said compartments are openat one end to facilitate the insertion and removal of the inner bags.

6. An assembly according to claim 1, wherein said strips are wasteproducts obtained in the working of plastic.

7. An assembly according to claim I, wherein at least one of said netsare of leno-weave.

8. An assembly according to claim 1, wherein at least one of said netsis made of strips of low pressure polyethylene.

9. An assembly according to claim 1, wherein at least one of said netsand said fill strips are of different thermoplastic materials.

10. An assembly according to claim 2, wherein said tight strips offabric are provided with eyelets through which pegs can be driven tofasten the mat to the ground.

11. An assembly according to claim 2, wherein said mat includes a borderof a tightly woven strip of fabric and said border is provided withmeans for fastening said mat to the ground.

a: a: s r s

1. An assembly for inhibiting shore erosion and the like comprising alarge outer mat, said mat being made of thermoplastic material andhaving an open net weave; means for dividing said mat into severalcompartments; a plurality of bags inside said mat compartments, saidbags being also made of thermoplastic material and having an open netweave; and entangled strips of thermoplastic material filling the innerbags.
 2. An assembly according to claim 1, wherein said means fordividing said mat are tight strips of fabric.
 3. An assembly accordingto claim 1, wherein said means for dividing said mat are seams.
 4. Anassembly according to claim 1, wherein said strips of thermoplasticmaterial are spliced.
 5. An assembly according to claim 1, wherein saidcompartments are open at one end to facilitate the insertion and removalof the inner bags.
 6. An assembly according to claim 1, wherein saidstrips are waste products obtained in the working of plastic.
 7. Anassembly according to claim 1, wherein at least one of said nets are ofleno-weave.
 8. An assembly according to claim 1, wherein at least one ofsaid nets is made of strips of low pressure polyethylene.
 9. An assemblyaccording to claim 1, wherein at least one of said nets and said fillstrips are of different thermoplastic materials.
 10. An assemblyaccording to claim 2, wherein said tight strips of fabric are providedwith eyelets through which pegs can be driven to fasten the mat to theground.
 11. An assembly according to claim 2, wherein said mat includesa border of a tightly woven strip of fabric and said border is providedwith means for fastening said mat to the ground.